To complement the information on morphological findings, we can also detect other aspects for the diagnosis of apocrine origin of tumor: presence of iron-positive granules in neoplastic cells3, presence of positive PAS material resistant to diastase in tumor cells and lumen, and positive immunelabeling in neoplastic cells3; presence of positive PAS material resistant to diastase in tumor cells and in lumen5, and positive immunereaction to two or three antigens comprising GCDFP-15 (gross cystic disease fluid protein-15), lisozime and CD-15.4 The gene discussed is PIP; the disease is neoplasm.